Coal-mine trap-door.



T. LEWIS.

COAL MINE TRAP DOOR.

APPLICATION FILED MAY25,1917.

Patented July 16, 1918.

2 SHEETS-SHEET 1.

T., LEWIS.

COAL MINE TRAP DOOR.

APPLICATION FILED MAY 25. 1911.

Patented July 16, 1918.

2 SHEETS-SHEET 2- human srmrns ra rnx'r ent ies THOMAS LEWIS, 0F FRANKFORT HEIGHTS, ILLINOIS.

COAL-MINE TRAP-DOOR.

Application filed-May 25, 1917.

To all whom it may concern Be it known that I, THOMAS LEWIS, a citizen of the United States, residing at Frankfort Heights, in the county of Franklin and State of Illinois, have invented certain new and useful Improvements .in Coal-Mine Trap-Doors; and I do hereby declare the following to be-a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in door structure s particularly designed for use in mines, although not necessarily limited to such use.

The invention has for its object to provide a door structure including novel features of construction, permitting the size of the door to be varied to adapt it for use in openings or passages of Various sizes.

Another object is the provision of a novel type of extensible door support including spring means normally retaining the door in closed position.

With these and other objects in View, the invention consists in the novel construction, combination and arrangement of parts as will be hereinafter specifically described, claimed and illustrated in the accompanying drawings, in which:

Figure 1 represents a front elevation, partly broken away, of the double door structure,

Fig. 2 represents a rear elevation of one of the door supports,

Fig. 8 represents a top plan View of one of the door structures,

Fig. 1 represents an enlarged detail view of part of the door closing mechanism, and

Fig. 5 represents a vertical sectional View through the door.

In Fig. 1 of the accompanying drawings, two of the doors are shown arranged in opposed relation to present a double door structure, but as the construction of both doors is identical a detail description of one will suffice.

Each door consists of a frame includ ing top and bottom members 6 and 7, carrying elbows 8 and 9 at the'terminals thereof. The side members of the door frame are extensible, permitting the size of the door to be varied, as desired, and include the bottom tubular sections 10, which are telescopically received in the top section 11, carried by the elbows 8 of the upper member Specification of Letters Patent.

Patented July 16, 1918.

Serial No. 171,062.

6. When the door frame is hung in a vertical position, as shown in Fig. 1, it is evident that the two parts of the frame may be separated or moved together to provide a door frame of the desired dimensions.

Two groups of inwardly directed teeth 12' are formed on the upper portion of the top member 6 on opposite sides of the center of the latter, and are adapted to cooperate with the links of the chains 13, which are attached at 141 within the lower sections 10 of the door frame and extend upwardly therethrough. Subsequent to adjusting the door frame, the links of the chains 13 are engaged with the inclined teeth 12 and the parts of the. door frame are thus locked against further separation.

Sheet metal covering plates 15 are secured to the extreme upper terminals of the opposed sides of the upper part of the door frame, including the top member 6 and side member sections 11, and the plates 15 project below the lower terminals of sections 11 and overlap the side plates 16 arranged upon the opposed sides of the lower part of the door frame, and secured to the bottom member 7 and the extreme lower ends of the side member sections 10.

Each door is supported by a post, designated generally by the numeral 17 which includes the lower section 18 of hollow formation and provided adjacent its lower terminal with an angular supporting arm 19, which extends through an aperture formed in the outer terminal of a supporting strap 20 attached to the lower portion of the door. The extreme lower terminal of the post section 18 is pointed, as indicated at 21, to facili section 18 slidably receives the upper section I 22, which is rigidly secured in adjusted position with relation to the section 18 by a set screw 23, and is provided at its upper terminal with a head 24 provided with a pointed terminal 25 adapted to anchor the upper terminal of the post in the wall of a mine tunnel or passage. The upper section 22 is also provided with an angular supporting arm 26, which extends through the apertured terminal of the supporting strap 27, carried by the upper portion of the door for sup porting the latter in position, with relation to the post.

A horizontally disposed cross bar 28 is fastened adjacent the upper terminal of the upper post section 22 and the side opposite the door. A. substantially V-shaped brace 29 is secured at its bight portion as at 30, to the upper post section 22 and secured at its opposite terminals, as at 31, to the cross bar 28. Arms 32 are pivotally secured at 33 to the opposite ends of the cross bar 28 and spring securing clips 34: are secured to the pivoted arms 32. Springs 35 are secured at one end to the clips 3 1, extend around the pivotally connected terminals of the arms 32 and the bar 28, and are secured at their opposite ends to spring securing clips 36 fastened adjacent the opposite ends of. the bar 28. The tension of the springs 35 normally tends to swing the arms 32 outwardly from the door.

Turn buckles 37 are connected at one end with the arms 32 and at their opposite ends with contractile springs 38. The springs 38 extend outwardly in converging planes and are attached at their opposite ends to the door or gate.

In use, two'oi the hinged doors are arranged in opposed relation, as clearly shown in Fig. 1, to present a double door structure and the doors are normally retained in closed position by the tension of the springs 38,

Copies of this patent may be obtained for assisted by the springs 35 acting upon the pivoted arms 32. The posts are rigidly anchored in position by extending the sections 18 and 22 thereof and embedding or inserting the pointed terminals 21 and 25 in the walls of the tunnel or passage or other structure. When adjusting the posts to the desired lengths, the chains 13 are disengaged from the teeth 12 and the parts of the doors being uncoupled they are adjusted simultaneously with the adjustment of the posts. The parts of the door aresubsequently secured in adjusted position by engaging the chains 13 with the teeth 12.

What I claim is:

at door structure including an extensible door frame including upper and lower parts, an extensible post including relatively movable upper and lower sections, andime'ans hingedly connecting the upper andlo-wersections of the post with the upper and lower parts of the door, respectively.

In testimony whereof I affiX my signature in presence of two witnesses, 3

7 THOMAS LEWIS. Witnesses: I

A THUR HAYS,

CALVIN CRAso.

five cents each, by addressing the Commissioner of Patents,

Washington, I). 0.? v 

